Legended[list,label] gives the specified legend label for the line defined by list.

ListLinePlot[{list1,list2,…}] by default takes the x coordinates for successive values in each of the to be successive integers starting at 1.

The setting DataRange->{xmin,xmax} specifies other ranges of x coordinates to use, with being associated with the last element in the longest of the .

With the default setting DataRange->Automatic, ListLinePlot[{{a11,a12},…,{an1,an2}}] will be taken to give x and y values for n points on a single line, rather than the y values for n separate lines each containing just two points.